Saturday, January 31, 2009
Thursday, January 29, 2009
visited 39 states (78%)
Create your own visited map of The United States or try another Douwe Osinga project
And these countries:
visited 12 states (5.33%)
Create your own visited map of The World or try another Douwe Osinga project
Hat tip: Julia.
Tuesday, January 27, 2009
It seems that my secret zircons are also obscene. This morning the client called up wondering where the results he wanted were. I emailed them last week. He hadn’t gotten them. A morning spent breaking a work email down into its component thoughts showed that his server thought my research was pornographic. Evidently the juxtaposition of ‘single’ and ‘dating’ in the same message was enough to classify my geochronology summary as pornography. I might email their webmaster and tell them their program is fucked- will the message get through?
Friday, January 23, 2009
We all know that the Hawaiian Islands are supposed to be huge blobs of Basalt piled up in the middle of the Pacific plate. So I was moderately surprised to find other rock types. Here is what I saw:
K-spar porphyry. Fine-grained matrix hard to ID, but presumably some sort of Monzonite. A late differentiate? On the East shore of Oahu.
Sandstone. Lithified beach sand. Cement type not obvious, but I’d guess some sort of silcrete. Possible silica precipitation due to pH change from groundwater to seawater? I honestly don’t know. Oahu and Kauai.
Dunite. Xenoliths in basalt. Kauai.
Felsic Gneiss. K-spar, plag, quartz, biotite folded foliated granite. Possibly an artifact.
Hotel countertop in Waikiki.
Posted by Chuck Magee at 11:08 PM
Tuesday, January 20, 2009
Monday, January 19, 2009
Last week the science debate 2008 folks sent me the following survey from the National Academies, asking what sort of science was important to me. Click to make more readable.
Hint: I've spent most of my career in tectonic hazards, hard rock geochemistry, and resource exploration and extraction.
On the other hand, some other less interesting Earth science topics seem to be doing pretty well, so go over and vote.
Saturday, January 17, 2009
Astronomers have detected huge plumes of methane on Mars, which may have a biological origin. Further work needs to be done, which will include spectroscopically analyzing the various associated sulfur species. This will allow sophisticated computer modeling simulators to digitally reconstruct the smell, which will be used to differentiate between biological and geologic processes. See Universe Today or The Planetary Society Blog for more mature interpretations.
Thursday, January 15, 2009
Chris over at Highly Allochthonous has just done an unusually good job at explaining what Wilson Cycles are, and the role they play in tectonic reconstruction. And he did it without using the most evil diagram in tectonics.
I don’t like the Wilson Cycle idea. I don’t deny that ocean basins open and close, but I think that it is too neat, too pat, and inadequately describes most real orogenies.
Take another look at that linked diagram. What is missing? I’ll give you a hint. If you live in Turkey, California, New Zealand, or China, it could kill you. If you still don’t know, think about which dimension that diagram considers expendable.
Crustal thickening and thinning is fairly easy to identify in the geologic record. The both initiate sedimentation, igneous activity, and/or metamorphism. Lateral tectonics, on the other hand, doesn’t leave nearly as big a mess behind. As a result, it can be (and often is) overlooked much more easily that a rift valley, or a mountain of ecolgite. And the open-and-shut presentation of Wilson cycles further de-emphasizes strike-slip motion.
I think that’s a mistake. Continents don’t just move back and forth; they also slide past each other and spin around. In most cases, continental collisions don't involve happen in the same orientation as the previous rifting (I'm ignoring the Alps tonight). Most of today’s active plate margins have some degree of lateral faulting associated with them. But the Wilson cycle doesn’t call attention to this fact.
Tuesday, January 13, 2009
Over at cosmic variance, unsolicited advice for post-docs suggests that it is a good idea to make papers good, which he defines as “interesting, even to people outside your immediate circle of friends.” However, in analytical science, broadening the appeal of a result often increases the chance that it is wrong.
An example. Suppose I discover a 4.3 billion year old rock. The oldest currently known rock is 4.2 billion years old, and the Earth is 4.5 billion years old. So my new rock is 33% closer to the beginning than the previous oldest rock was.
I will use endmember examples to describe how to interpret my new discovery. The conservative approach is to say that everything I know about my rock can only be applied to that particular rock, and says nothing about the rock 10 meters away, the rest of the tectonic block, or the Earth as a whole. The speculative approach is to say that my rock is representative of all 200 million-year-old earth-sized planets around all mid-sized stars in the universe.
Now, the latter explanation will obviously interest a larger number of people- astrobiologists, astronomers, meteoriticists, and all sorts of geochemists would like to know about early planetary conditions. The former approach would interest only the thre guys who found that particular rock. So by the CV definition listed above, the speculative approach would be a better interpretation. But the problem is that extrapolation to the entire universe is also more likely to be wrong.
How far to extrapolate one’s results is one of those touchy subjects in science. Different people draw the line in different places. Compared to any one person’s preferred amount of extrapolation, anyone who extrapolates more is an irresponsible yahoo who is putting disinformation into the literature and leading generations astray. Anyone who extrapolates less is a curmudgeonly cherry-picking data hoarder who refuses to publish all but his least interesting work.
The key to navigating the treacherous waters of data interpretation is to know that different researchers- and different departments- have different standards by which they judge the correct amount of extrapolation.
One high profile example of this is in the field of Hadean zircons, which were discussed in the New York Times article I blogged about last month. The oxygen isotope work on these samples was originally done by two groups, one at UCLA and one at UW-Madison. In general, the UW group was conservative about their results, while the UCLA group was more speculative. So at conferences and seminars, proponents of the conservative approach would imply that the UCLA results included bad data, while the more optimistic scientists suggested that the UW-Madison group was committing selection bias by throwing out good data.
If y’all want to argue about who is right in comments, feel free. The important point for scientists in training to realize is that when you are writing your own papers, the amount of extrapolation you do will be criticized as either too much or too little depending on who reads it. So if you’re aiming to work in a conservative department, writing speculative papers probably won’t endear you. And vice versa.
Sunday, January 11, 2009
If all goes to plan, today is my last day of unemployment. Back in early November, when I got my notice, one of the first things I did was to call various collaborators, in order to tell them that I would not be able to continue work on our projects. One of those people asked me if this meant I was looking for work, and when I said yes, he suggested I swing by for a chat. A few weeks later he did, and a job offer materialized as a result.
I also did a lot of calling and emailing around to other people I knew. Of those folks, those in a similar position to me (mid-early career 30-something industry geologists) were most pessimistic, with many saying that they had just weathered rounds of layoffs the weeks before. My best leads and tentative offers came from non-geologists with whom I had interacted professionally- representatives of instrument manufacturers, contractors, government agency personnel, and even academics.
The lesson here, far as I can tell, is to be nice, professional, and competent no matter whom you’re dealing with. ‘cause you never know which of those people will be the one who is hiring when it all comes crashing down again.
Friday, January 09, 2009
OK folks, this is the part of the blog where any of you who are in real financial difficulty get to say a big fuck you in the comments section. I’ve been vacationing in Hawaii for the past 2 weeks. While unemployed. 'cause it's not like I could have spent the time at work, or anything. I hope you all had wonderful holidays as well.
This is the active end of the island chain, where red hot lava is flowing into the sea.
And this is the weathering end, where red cool clay is doing the same.
Tuesday, January 06, 2009
According to the federal government of the United States of America*, ice is a liquid. This classification has a number of implications for Earth and planetary sciences, the study of which is often funded by the same federal government. A few of these are:
- Europa, Ganymede, and Callisto are water worlds, completely covered in ocean.
- The various Mars probes have found unequivocal evidence for liquid water on modern Mars, both in the northern polar cap and in the subsurface below the Phoenix probe.
- It is too late to stop anthropogenic climate change from melting Earth’s polar ice caps; they are liquid already.
- Ice sheets and floods can’t possibly be geologically distinguishable, as they are the same process.
- The Snowball Earth hypothesis is an exercise in semantics
- The Titanic must have been sunk by a conspiracy theory.